Question: Simplify the following expression: $k = \dfrac{50x}{50y + 10} + \dfrac{40y + 50x}{50y + 10}$ You can assume $x,y,z \neq 0$.
Answer: Since the expressions have the same denominator we simply combine the numerators: $k = \dfrac{50x + 40y + 50x}{50y + 10}$ $k = \dfrac{100x + 40y}{50y + 10}$ The numerator and denominator have a common factor of $10$, so we can simplify $k = \dfrac{10x + 4y}{5y + 1}$